Gearbox oil circuit lubrication structure, gearbox and extended-range dual-motor power assembly

Abstract

The application belongs to the technical field of transmission equipment, and particularly relates to an oil circuit lubricating structure of a gearbox, the gearbox and an extended-range dual-motor power assembly. The oil circuit lubricating structure comprises a side oil storage groove, a bottom oil groove and an oil pump oil suction hole arranged on the shell of the gearbox. A separation structure is arranged between the side oil storage groove and the bottom oil groove, and the separation structure separates the side oil storage groove from the bottom oil groove. A communication oil channel for communicating with each other is arranged between the side oil storage groove and the bottom oil groove, and the oil pump oil suction hole is arranged in the bottom oil groove. In the horizontal or small-inclination working condition, the arc-shaped structure can effectively prevent the lubricating oil from flowing freely between the two cavities, and prevent the lubricating oil in the bottom oil groove from entering the side oil storage groove, so as to reduce the oil stirring loss of the high-speed rotating part. When climbing at a large inclination, the lubricating oil collected in the side oil storage groove can continuously supplement the oil pump through the communication oil channel, so as to ensure the stable work of the lubricating system.

Description

Technical Field

[0001] This invention belongs to the field of transmission equipment technology, specifically relating to an oil circuit lubrication structure for a gearbox, a gearbox, and a range-extended dual-motor powertrain. Background Technology

[0002] With the rapid development of range-extended electric vehicle technology, the range-extended dual-motor powertrain has been widely used in SUVs, off-road vehicles, and multi-condition commercial vehicles due to its advantages such as compact structure, fast power response, and no range anxiety. These vehicles often face complex conditions such as mountain roads, steep slopes, and steep inclines on unpaved roads, resulting in frequent occurrences of large longitudinal tilt and lateral tilt during driving.

[0003] Existing range-extended dual-motor powertrains mostly employ a traditional oil-immersion lubrication system with passive splash lubrication and fixed oil supply channels. The oil circuit layout, oil sump volume, oil return, and oil guide structures are all designed to match the vehicle's horizontal, stationary operating conditions. Under conditions of steep inclines and continuous inclines on long slopes, the lubricating oil level in the transmission is prone to shift or localized low oil levels. This can lead to insufficient oil supply, oil cut-off, and inadequate lubrication of critical friction pairs such as bearings, gears, high-speed meshing pairs, motor rotor support structures, and oil pump suction ports.

[0004] In existing lubrication circuits, oil is pumped into an oil cooler (for cooling the oil) and then filtered to remove impurities and foreign matter before entering the cavities of each motor and its shaft system. In the motor cavity, oil is sprayed into the P1 / P3 motor cavities through small holes in the oil pipe via an internal cooling circuit. In the shaft system, oil enters the shaft system through small holes in each bearing chamber via an internal cooling circuit, where it is cooled by splashing from gears and bearings before circulating. This lubrication circuit is only suitable for level and low-angle driving conditions. It lacks dedicated oil circuit zoning, oil collection, anti-cavitation, and directional oil supply optimization for the range-extended dual-motor integrated architecture and high-angle climbing steady-state conditions. Therefore, it cannot meet the long-term reliable lubrication and cooling requirements of the powertrain under off-road and mountainous terrain with steep inclines, exhibiting significant technical shortcomings. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide an oil circuit lubrication structure for a transmission, a transmission and a range-extended dual-motor powertrain, to solve the technical problem of insufficient oil pump suction and reduced lubrication reliability caused by the displacement of lubricating oil due to gravity under large tilt angle conditions.

[0006] In a first aspect, this application provides an oil lubrication structure for a transmission, including a side oil reservoir, a bottom oil reservoir, and an oil pump suction port disposed on the transmission housing. A partition structure is provided between the side oil reservoir and the bottom oil reservoir to separate them. A connecting oil passage is provided between the side oil reservoir and the bottom oil reservoir to connect them. The oil pump suction port is disposed in the bottom oil reservoir.

[0007] Optionally, the partition structure is an arc-shaped structure. In the horizontal state, the height of the arc-shaped structure extending upward from the bottom of the gearbox housing is 0.3-0.5 times the height of the inner cavity of the gearbox housing.

[0008] Optionally, the connecting oil passage is an inclined flow channel, with one port located at the bottom area of ​​the bottom oil tank and below the oil pump suction hole, and the other port above the oil pump suction hole and below the top of the partition structure.

[0009] Optionally, the side oil reservoir is a groove structure provided along the side wall of the gearbox housing, and its volume is 10%-30% of the total volume of the bottom oil reservoir.

[0010] Optionally, the height difference between the inlet end face of the oil pump suction hole and the bottom of the bottom oil tank is 5-20mm.

[0011] Optionally, the cross-sectional shape of the connecting oil passage is circular, elliptical, or rectangular.

[0012] Optionally, the cross-sectional area of ​​the connecting oil passage is 50-150 mm². 2 .

[0013] Optionally, the height of the partition structure extending upward from the bottom of the gearbox housing is 10-100mm.

[0014] Secondly, this application provides a transmission, including a transmission body and an oil lubrication structure as described above.

[0015] Thirdly, this application provides a range-extended dual-motor powertrain including a power battery, a power motor, a range extender, and a gearbox as described above, wherein the gearbox is connected to the power motor via a rotating shaft.

[0016] The beneficial effects of this application are: The oil lubrication structure of the transmission provided in the first aspect of this application, by setting a side oil reservoir and a bottom oil reservoir separated by a baffle structure in the transmission housing, and configuring a connecting oil passage between the two, effectively intercepts and collects the lubricating oil that is deflected by gravity under high tilt angle conditions, so as to prevent the oil pump suction hole from being exposed and cutting off the oil supply. When the vehicle returns to stability, the oil flows smoothly back to the bottom oil reservoir through the connecting oil passage to ensure continuous oil supply. This effectively solves the problem of insufficient oil suction caused by oil displacement under complex tilt conditions, and significantly improves the lubrication and heat dissipation reliability of key friction pairs such as bearings, gears and motors, so as to meet the long-term stable operation requirements of the range-extended dual-motor powertrain under extreme road conditions such as off-road and steep slopes.

[0017] The gearbox provided in the second aspect of this application effectively solves the problem of insufficient oil supply under large tilt angle conditions by integrating a side oil reservoir, an optimized oil pump suction hole, and a connecting oil passage into an oil circuit lubrication structure, and significantly improves the lubrication reliability under complex road conditions.

[0018] The range-extended dual-motor powertrain provided in the third aspect of this application integrates a gearbox with an optimized oil circuit lubrication structure. Through the side oil reservoir, precisely arranged oil pump suction holes and connecting oil passages, it effectively solves the problem of insufficient oil supply to the gearbox under large tilt angle conditions, and significantly improves the lubrication reliability under complex road conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a traditional gearbox housing; Figure 2 This is a schematic diagram of the structure of a gearbox housing including an oil lubrication system, provided in an embodiment of this application. Figure 3 A cross-sectional structural diagram of a gearbox housing including an oil lubrication system, provided in an embodiment of this application; Figure 4 A schematic diagram of the oil lines in the P3 / P1 chambers of the gearbox provided in this application embodiment under the conditions of 0% slope and P3 speed of 500 rpm; Figure 5 A schematic diagram of the oil lines in the P3 / P1 chambers of the gearbox provided in this application embodiment under the conditions of 0% slope and P3 speed of 7000rpm; Figure 6 A schematic diagram of the oil lines in the P3 / P1 chambers of the gearbox provided in this application embodiment under the conditions of a 15% slope and a P3 speed of 500 rpm; Figure 7 A schematic diagram of the oil lines in the P3 / P1 chambers of the gearbox provided in this application embodiment under the conditions of a 30% slope and a P3 speed of 500 rpm; Figure 8A schematic diagram of the oil lines in the P3 / P1 chambers of the gearbox provided in this application embodiment under the conditions of a 45% slope and a P3 speed of 500 rpm; Figure 9 A schematic diagram of the oil lines in the P3 / P1 chambers of the gearbox provided in this application embodiment under the conditions of a 60% slope and a P3 speed of 500 rpm.

[0020] In the diagram: 100, gearbox housing; 101, side oil reservoir; 102, connecting oil passage; 103, oil pump suction hole; 104, partition structure; 105, bottom oil reservoir; 106, differential shaft. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] like Figure 2 and Figure 3 As shown, the first aspect of this application provides an oil lubrication structure for a transmission, including a side oil reservoir 101, a bottom oil reservoir 105, and an oil pump suction port 103 disposed in the transmission housing 100. A partition structure 104 is provided between the side oil reservoir 101 and the bottom oil reservoir 105, separating the side oil reservoir 101 and the bottom oil reservoir 105. A connecting oil passage 102 is provided between the side oil reservoir 101 and the bottom oil reservoir 105 for connecting them. The inlet of the connecting oil passage 102 is located in the side oil reservoir 101, and the oil pump suction port 103 is disposed in the bottom oil reservoir 105.

[0023] The transmission oil lubrication structure provided in the first aspect of this application, under horizontal or small tilt conditions, effectively separates the side oil reservoir 101 from the bottom oil reservoir 105 using the partition structure 104, allowing the bottom oil reservoir 105 to maintain a normal oil level to meet routine lubrication needs. Simultaneously, the side oil reservoir 101, as an independent oil storage space, can collect splashed oil, reducing oil churning losses. When the vehicle enters a steep incline or continuous tilt condition, the lubricating oil in the bottom oil reservoir 105 accumulates towards the lower side due to gravity. At this time, through the communicating vessel principle of the connecting oil passage 102, the lubricating oil accumulated in the side oil reservoir 101 can... The oil automatically flows to the bottom oil tank 105, ensuring that the oil pump suction hole 103 is always submerged in lubricating oil, avoiding cavitation. At the same time, the side oil storage tank 101 serves as a temporary collection and buffer area for lubricating oil, which can quickly replenish the oil in the bottom oil tank 105 when the oil level shifts. This ensures that key friction pairs such as bearings, gears, and high-speed meshing pairs can still obtain continuous and sufficient lubrication and heat dissipation under extreme working conditions. This solves the technical problems of insufficient oil supply and oil cut-off caused by oil level shift under large tilt angle conditions in the prior art, and helps to improve the reliability and durability of the range-extended dual-motor powertrain under complex road conditions.

[0024] It should be noted that, as Figure 1 As shown, traditional oil lubrication mechanisms lack the partition structure 104 and the connecting oil passage 102. In traditional dual-motor drive assemblies, the lubrication oil passages are interconnected without partitions, meaning the oil can move freely between chambers P1 and P3, causing temperature and oil pressure to influence each other. Adding the partition structure 104 reduces interference between the high-speed oil churning processes in P1 and P3, lowering churning losses. Under slope conditions of 60% or greater, due to gravity and the presence of the partition structure 104, oil accumulates in the P3 shaft cavity, causing the oil pump to experience cavitation.

[0025] It should also be noted that unless otherwise specified, the positional and height relationships of the components and parts mentioned above and below refer to the relationship when the gearbox is in a horizontal position.

[0026] In some embodiments, the partition structure 104 is an arc-shaped structure. In the horizontal state, the height of the arc-shaped structure extending upward from the bottom of the gearbox housing 100 is 0.3-0.5 times the height of the inner cavity of the gearbox housing 100.

[0027] Specifically, the baffle structure 101 adopts an arc-shaped design with a height 0.3-0.5 times the height of the inner cavity of the gearbox housing 100, which can balance the needs of oil storage and return flow. If the height is too low, the volume of the side oil reservoir will be insufficient, and it will not be able to effectively collect oil and prevent cavitation under large angles; if the height is too high, it will hinder the return flow of oil through the connecting oil passage, increase flow resistance, and occupy the space of the bottom oil reservoir. Compared with right-angle baffles, the arc-shaped structure can reduce oil flow turbulence and stagnation, so that the lubricating oil can smoothly transition when accumulating at large angles and when returning horizontally. This ensures the reliability of oil storage under extreme conditions and the efficiency of oil circulation under normal conditions, while avoiding stress concentration and improving structural durability.

[0028] In some embodiments, the connecting oil passage 102 is an inclined flow channel, with one port located in the bottom region of the bottom oil tank 105 and lower than the oil pump suction hole 103, and the other port higher than the oil pump suction hole 103 and lower than the top of the partition structure 104.

[0029] Specifically, the connecting oil passage 102 adopts an inclined flow channel design, with its high port located on the side of the oil reservoir 101 (higher than the oil pump suction hole 103 and lower than the top of the partition structure 104), and its low port located in the bottom area of ​​the bottom oil tank 105 (lower than the oil pump suction hole 103). When the vehicle returns from a large tilt angle to a horizontal or small tilt angle, the lubricating oil collected in the side oil reservoir 101 flows smoothly back from the high port to the deepest part of the bottom oil tank 105 along the inclined connecting oil passage 102 under the action of gravity. This height difference layout not only prevents the oil from overflowing the partition structure 104 or directly rushing to the oil pump suction hole 103 and generating air bubbles, but also ensures that the returned oil directly converges below the oil pump suction hole 103, so that the oil pump suction hole 103 is always kept at a sufficient and stable oil level, thereby ensuring a continuous and reliable oil supply under complex working conditions.

[0030] In some embodiments, the side oil reservoir 101 is a groove structure provided along the side wall of the gearbox housing 100, and its volume is 10%-30% of the total volume of the bottom oil reservoir 105.

[0031] Specifically, an independent oil storage area is formed without increasing the overall volume. In horizontal operation, it serves as a buffer and collection area to collect splashed lubricating oil and reduce churning losses. In steep incline operation, the lubricating oil accumulates in the tank due to gravity, and its reasonable volume satisfies both replenishment needs and prevents prolonged stagnation. The groove structure also acts as a guide, directing the lubricating oil quickly to the inlet of the connecting oil passage 102, ensuring timely replenishment to the bottom oil tank 105 under extreme conditions and maintaining the oil pump suction hole 103 submerged.

[0032] In some embodiments, the oil pump suction port 103 is located at the lowest point of the side oil reservoir 101, and the height difference between the inlet end face of the oil pump suction port 103 and the bottom of the bottom oil reservoir 105 is 5-20mm. Thus, by utilizing the principle of gravity, the oil that has shifted under large tilt angle conditions naturally collects around the oil pump suction port 103, ensuring continuous and stable oil suction from the oil pump to prevent cavitation. At the same time, the reasonable suspension height of 5-20mm effectively prevents the oil pump suction port 103 from directly contacting the bottom and sucking in deposited impurities and metal shavings, preventing oil circuit blockage and component wear, while also minimizing oil residue at the bottom, improving the utilization rate of lubricating oil and the reliability of lubrication under complex operating conditions.

[0033] In some embodiments, the cross-sectional shape of the connecting oil passage 102 is circular, elliptical, or rectangular.

[0034] In some embodiments, the cross-sectional area of ​​the connecting oil passage 102 is 50-150 mm². 2 .

[0035] Specifically, the cross-sectional area of ​​the aforementioned connecting oil passage 102 can prevent the cross-sectional area from being too small, thus limiting the lubricating oil flow and affecting the oil replenishment efficiency; it can also reduce the risk of excessively low oil flow rate due to an excessively large cross-sectional area, thus increasing the risk of stagnation. Under horizontal operating conditions, the aforementioned cross-sectional area can ensure smooth lubricating oil flow and reduce energy loss; under large tilt angle operating conditions, 50-150mm 2 The cross-sectional area, combined with the inclined flow channel structure, allows the lubricating oil to flow rapidly under the action of gravity, ensuring timely replenishment to the bottom oil tank 105.

[0036] In some embodiments, the height of the partition structure 104 extending upward from the bottom of the gearbox housing 100 is 10-100 mm. Exemplarily, the height of the partition structure 104 can be any typical but non-limiting point value or a value between any two points, such as 10 mm, 20 mm, 30 mm, 40 mm, or 50 mm.

[0037] A second aspect of this application provides a transmission, including a transmission body and the oil lubrication structure described above.

[0038] The gearbox provided in the second aspect of this application, through an oil circuit lubrication structure consisting of an integrated side oil reservoir 101, an optimized oil pump suction hole 103, and a connecting oil passage 102, effectively solves the problem of insufficient oil supply under large tilt angle conditions and significantly improves lubrication reliability under complex road conditions.

[0039] like Figure 4As shown, under the low-speed condition of 500 rpm, P3 has low gear linear velocity, small centrifugal force, no high-speed oil churning resistance, and no high-speed splashing of lubricating oil. At this time, due to the presence of the partition structure 104, the oil level (L1) in the P3 chamber is higher than the oil level (L2) in the P1 chamber, while the oil level (L2) in the P1 chamber is higher than the oil pump suction hole 103.

[0040] like Figure 5 As shown, under the high-speed condition of 7000 rpm, the gear linear velocity of P3 is high and the centrifugal force is large, and most of the lubricating oil is splashed or thrown into the other gears and bearings. At this time, the side oil reservoir 101 can temporarily store some of the splashed lubricating oil, so that the oil level (L2) in the P1 chamber is higher than the oil level (L1) in the P3 chamber, thereby reducing the oil churning loss of P3.

[0041] like Figure 6 As shown, in operating condition 3: uphill, gradient 15%, P3 speed 500 rpm. Compared to operating condition 1, the oil line (L1) in the P3 chamber in operating condition 3 rises and gradually exceeds the oil passage opening of the connecting oil passage 102 at the side oil reservoir 101; at the same time, the oil line (L2) in the P1 chamber in operating condition 3 decreases, but remains above the oil pump suction hole 103. Furthermore, due to the presence of the partition structure 104, the oil chambers of P3 and P1 are isolated.

[0042] like Figure 7 As shown, in operating condition 4: uphill, gradient 30%, P3 speed 500 rpm. Compared to operating condition 3, the oil line (L1) in the P3 chamber in operating condition 4 is further raised and gradually overflows the oil passage opening of the connecting oil passage 102 at the side oil reservoir 101; at the same time, the oil line (L2) in the P1 chamber in operating condition 4 is further lowered, but remains higher than the oil pump suction hole 103. Meanwhile, due to the presence of the partition structure 104, the oil chambers of P3 and P1 are isolated.

[0043] like Figure 8 As shown, in operating condition 5: uphill, gradient 45%, P3 speed 500 rpm. Compared to operating condition 4, the oil line (L1) in the P3 cavity in operating condition 5 is further raised, completely higher than the oil passage opening of the connecting oil passage 102 at the side oil reservoir 101; at this time, the oil line (L2) in the P1 cavity in operating condition 5 is further lowered, gradually approaching the oil pump suction hole 103, but the oil accumulated in the P3 cavity continues to flow into the P1 cavity through the connecting oil passage 102, so that the oil line in the P1 cavity is always higher than the oil pump suction hole 103. At the same time, due to the presence of the partition structure 104, the oil cavities of P3 and P1 are isolated.

[0044] like Figure 9As shown, in operating condition 6: uphill, gradient 60%, P3 speed 500 rpm. Compared to operating condition 5, in operating condition 6, most of the lubricating oil is concentrated in the P3 cavity due to gravity and gear churning. The lubricating oil in the P3 cavity can be stably introduced into the P1 cavity through the connecting oil passage 102, ensuring that the oil line (L2) in the P1 cavity does not drop to the oil pump suction hole 103. At the same time, due to the presence of the partition structure 104, the oil cavities of P3 and P1 are isolated.

[0045] Under low-speed uphill conditions (500 rpm), the gear linear velocity is low, the centrifugal force is small, and there is no high-speed oil churning or splashing effect, so the lubricating oil is mainly distributed by gravity. As the uphill slope gradually increases from 15% to 60%, the lubricating oil continuously accumulates in the P3 cavity, causing the oil level in the P3 cavity to rise continuously and overflow the oil passage opening of the connecting oil passage 102; the oil level in the P1 cavity gradually decreases, approaching the oil pump suction hole 103. At the same time, due to the presence of the partition structure 104, the oil cavities of P3 and P1 are isolated. As the slope increases, the oil in the P3 cavity gradually replenishes the P1 cavity through the side oil reservoir 101 and the connecting oil passage 102, ensuring that the oil level L2 in the P1 cavity is higher than the oil pump suction hole 103.

[0046] It should be noted that the gearbox in this application is part of a range-extended dual-motor powertrain. The motor designations are generally based on their mounting positions, with 0, 1, 2, 3, and 4 representing different motor mounting locations. P1: The motor is located before the gearbox, mounted on the engine crankshaft, and acts as a generator. P1 cavity: A cavity within the dual-motor housing that houses the P1 generator, P1 input shaft, and P1 output shaft. P3: The motor is located on the gearbox output side, at the front of the differential, and acts as a drive motor. P3 cavity: A cavity within the dual-motor housing that houses the P3 drive motor, reducer gears, and differential assembly. The side oil reservoir 101 is an important component of the P3 cavity; this location is generally the oil cavity where the differential assembly is located. The bottom oil reservoir stores lubricating oil flowing from the P3 oil cavity to the P1 oil cavity, preventing the oil pump suction hole 103 from being sucked dry.

[0047] A third aspect of this application provides a range-extended dual-motor powertrain, including a power battery, a power motor, a range extender, and the aforementioned gearbox, wherein the gearbox and the power motor are connected via a rotating shaft.

[0048] The range-extended dual-motor powertrain provided in the third aspect of this application integrates a gearbox with an optimized oil circuit lubrication structure. Through the side oil reservoir 101, the precisely arranged oil pump suction hole 103, and the connecting oil passage 102, it effectively solves the problem of insufficient oil supply to the gearbox under large tilt angle conditions, and significantly improves the lubrication reliability under complex road conditions. At the same time, the dual motors and the range extender work together to achieve efficient energy management and power output, and enhance the adaptability of the whole vehicle under various operating conditions and the system durability.

[0049] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0050] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A lubrication structure for a transmission oil circuit, characterized in that, The system includes a side oil reservoir (101), a bottom oil reservoir (105), and an oil pump suction port (103) disposed on the gearbox housing (100). A partition structure (104) is provided between the side oil reservoir (101) and the bottom oil reservoir (105), which separates the side oil reservoir (101) from the bottom oil reservoir (105). A connecting oil passage (102) is provided between the side oil reservoir (101) and the bottom oil reservoir (105) for connecting them. The oil pump suction port (103) is disposed in the bottom oil reservoir (105).

2. The oil lubrication structure of the gearbox according to claim 1, characterized in that, The partition structure (104) is an arc-shaped structure. In the horizontal state, the height of the arc-shaped structure extending upward from the bottom of the gearbox housing (100) is 0.3-0.5 times the height of the inner cavity of the gearbox housing (100).

3. The oil circuit lubrication structure of the gearbox according to claim 1 or 2, characterized in that, The connecting oil passage (102) is an inclined flow channel, with one port located in the bottom area of ​​the bottom oil tank (105) and lower than the oil pump suction hole (103), and the other port higher than the oil pump suction hole (103) and lower than the top of the partition structure (104).

4. The oil circuit lubrication structure of the gearbox according to claim 3, characterized in that, The side oil reservoir (101) is a groove structure provided along the side wall of the gearbox housing (100), and its volume is 10%-30% of the total volume of the bottom oil reservoir (105).

5. The oil lubrication structure of the gearbox according to claim 1, characterized in that, The height difference between the inlet end face of the oil pump suction hole (103) and the bottom of the bottom oil tank (105) is 5-20mm.

6. The oil lubrication structure of the gearbox according to claim 1, characterized in that, The cross-sectional shape of the connecting oil passage (102) is circular, elliptical or rectangular.

7. The oil circuit lubrication structure of the gearbox according to claim 6, characterized in that, The cross-sectional area of ​​the connecting oil passage (102) is 50-150 mm. 2 .

8. The oil lubrication structure of the gearbox according to claim 1, characterized in that, The height of the partition structure (104) extending upward from the bottom inside the gearbox housing (100) is 10-100mm.

9. A gearbox, characterized in that, It includes the gearbox body and the oil lubrication structure as described in any one of claims 1-8.

10. A range-extended dual-motor powertrain, characterized in that, It includes a power battery, a power motor, a range extender, and a gearbox as described in claim 9, wherein the gearbox is connected to the power motor via a rotating shaft.

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